Apparatus and method for transmitting and receiving signal in multimedia system

ABSTRACT

A transmitting apparatus and an operating method for the apparatus in a multimedia system are provided. The operating method includes inputting at least one network layer packet, generating a link layer packet based on the at least one network layer packet, and transmitting the link layer packet. The link layer packet includes a header including information indicating a packet type of the at least one network layer packet, information indicating whether the link layer packet includes a single network layer packet, and information indicating an identifier related to the at least one network layer packet.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation application of prior application Ser.No. 15/251,489, filed on Aug. 30, 2016, which was based on and claimedthe benefit priority under 35 U.S.C § 119(a) of a Korean patentapplication number 10-2015-0122808, filed on Aug. 31, 2015, and Koreanpatent application number 10-2016-0005354, filed on Jan. 15, 2016, inthe Korean Intellectual Property Office the entire disclosure of each ofwhich is hereby incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present disclosure relates to an apparatus and method fortransmitting and receiving a signal in a multimedia system. Moreparticularly, the present disclosure relates to an apparatus and methodfor transmitting and receiving a signal in a multimedia systemsupporting a link layer protocol.

BACKGROUND

Recently, various devices for broadcast services have been provided, sothere is a need for a method of supporting various receiving schemes inthe broadcast services.

Further, demand for data transport for various formats including apacket which is based on an Internet protocol (IP) as well as MovingPicture Experts Group phase 2 (MPEG 2)-transport stream (TS) packettransport.

Generally, a layer which is between a physical layer and an IP layer ina communication system is referred to as link layer, and a design forthe link layer is optimized according to a type of a service provided bythe communication system and a characteristic of the physical layer.

Therefore, there is a need for a scheme for optimizing a link layerprotocol for a broadcast system by considering a characteristic of aphysical layer of a broadcast network and a broadcast service.

The above information is presented as background information only toassist with an understanding of the present disclosure. No determinationhas been made, and no assertion is made, as to whether any of the abovemight be applicable as prior art with regard to the present disclosure.

SUMMARY

Aspects of the present disclosure are to address at least theabove-mentioned problems and/or disadvantages and to provide at leastthe advantages described below. Accordingly, an aspect of the presentdisclosure is to provide an apparatus and method for transmitting andreceiving a signal in a multimedia system.

Another aspect of the present disclosure is to provide an apparatus andmethod for transmitting and receiving a signal in a multimedia systemsupporting a link layer protocol.

Another aspect of the present disclosure is to provide an apparatus andmethod for transmitting and receiving information related to asub-stream included in a link layer packet in a multimedia systemsupporting a link layer protocol.

Another aspect of the present disclosure is to provide an apparatus andmethod for transmitting and receiving information related to a linklayer packet carrying a plurality of sub-streams in a multimedia systemsupporting a link layer protocol.

Another aspect of the present disclosure is to provide an apparatus andmethod for effectively transmitting and receiving various types ofservices in a multimedia system supporting a link layer protocol.

Another aspect of the present disclosure is to provide an apparatus andmethod for filtering a sub-stream in a link layer packet in a multimediasystem supporting a link layer protocol.

In accordance with an aspect of the present disclosure, an operatingmethod of a transmitting apparatus in a multimedia system is provided.The operating method includes inputting at least one network layerpacket, generating a link layer packet based on the at least one networklayer packet, and transmitting the link layer packet, wherein the linklayer packet includes a header including information indicating a packettype of the at least one network layer packet, information indicatingwhether the link layer packet includes a single network layer packet,and information indicating an identifier related to the at least onenetwork layer packet.

In accordance with another aspect of the present disclosure, anoperating method of a transmitting apparatus in a multimedia system isprovided. The operating method includes generating a link layer packetincluding a header including information related to a first sessionamong a plurality of sessions if the plurality of sessions are includedin a physical layer channel signal, and transmitting the link layerpacket, wherein, if the plurality of sessions include Internet protocol(IP) sessions, the information related to the first session includes anidentifier of the first session and a context identifier of an IP streamto which a header compression scheme is applied.

In accordance with another aspect of the present disclosure, atransmitting apparatus is provided. The transmitting apparatus includesat least one processor configured to input at least one network layerpacket, and to generate a link layer packet based on the at least onenetwork layer packet, and a transmitter configured to transmit the linklayer packet, wherein the link layer packet includes a header includinginformation indicating a packet type of the at least one network layerpacket, information indicating whether the link layer packet includes asingle network layer packet, and information indicating an identifierrelated to the at least one network layer packet.

In accordance with another aspect of the present disclosure, atransmitting apparatus in a multimedia system is provided. Thetransmitting apparatus includes at least one processor configured togenerate a link layer packet including a header including informationrelated to a first session among a plurality of sessions if theplurality of sessions are included in a physical layer channel signal,and a transmitter configured to transmit the link layer packet, wherein,if the plurality of sessions include IP sessions, the informationrelated to the first session includes an identifier of the first sessionand a context identifier of an IP stream to which a header compressionscheme is applied.

Other aspects, advantages, and salient features of the disclosure willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses various embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainembodiments of the present disclosure will be more apparent from thefollowing description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 schematically illustrates a system architecture of a multimediasystem according to an embodiment of the present disclosure;

FIG. 2 schematically illustrates an architecture of a broadcast linklayer of a multimedia system according to an embodiment of the presentdisclosure;

FIG. 3 schematically illustrates a format of an advanced televisionsystems committee-mobile/handheld (ATSC) link-layer protocol (ALP)packet in a multimedia system according to an embodiment of the presentdisclosure;

FIG. 4 schematically illustrates a format of a base header included inan ALP packet in a multimedia system according to an embodiment of thepresent disclosure;

FIG. 5 schematically illustrates a format of an additional header in acase that a payload includes a single input packet in a multimediasystem according to an embodiment of the present disclosure;

FIG. 6 schematically illustrates a format of an additional header in acase that a payload includes a part of a single input packet in amultimedia system according to an embodiment of the present disclosure;

FIG. 7 schematically illustrates a format of an additional header in acase that a payload includes a plurality of input packets in amultimedia system according to an embodiment of the present disclosure;

FIG. 8 schematically illustrates a format of an optional header includedin an ALP packet in a multimedia system according to an embodiment ofthe present disclosure;

FIG. 9 schematically illustrates a format of an additional header in acase that a payload includes a link layer signaling in a multimediasystem according to an embodiment of the present disclosure;

FIG. 10 schematically illustrates an example of a process oftransmitting data in a transmitting apparatus in a multimedia systemsupporting a link layer protocol according to an embodiment of thepresent disclosure;

FIG. 11 schematically illustrates a process of configuring a channel mapin a receiving apparatus in a multimedia system supporting a link layerprotocol according to an embodiment of the present disclosure;

FIG. 12 schematically illustrates another example of a process oftransmitting data in a transmitting apparatus in a multimedia systemsupporting a link layer protocol according to an embodiment of thepresent disclosure;

FIG. 13 schematically illustrates a process of compressing a userdatagram protocol (UDP)/Internet protocol (IP) header in a multimediasystem supporting a link layer protocol according to an embodiment ofthe present disclosure;

FIG. 14 schematically illustrates a process of recovering a UDP/IPheader in a receiving apparatus in a multimedia system supporting a linklayer protocol according to an embodiment of the present disclosure;

FIG. 15 schematically illustrates an inner structure of a transmittingapparatus in a multimedia system according to an embodiment of thepresent disclosure; and

FIG. 16 schematically illustrates an inner structure of a receivingapparatus in a multimedia system according to an embodiment of thepresent disclosure.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the present disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thepresent disclosure. In addition, descriptions of well-known functionsand constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of the presentdisclosure. Accordingly, it should be apparent to those skilled in theart that the following description of various embodiments of the presentdisclosure is provided for illustration purpose only and not for thepurpose of limiting the present disclosure as defined by the appendedclaims and their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

Although ordinal numbers such as “first,” “second,” and so forth will beused to describe various components, those components are not limitedherein. The terms are used only for distinguishing one component fromanother component. For example, a first component may be referred to asa second component and likewise, a second component may also be referredto as a first component, without departing from the teaching of thepresent disclosure. The term “and/or” used herein includes any and allcombinations of one or more of the associated listed items.

It will be further understood that the terms “comprises” and/or “has,”when used in this specification, specify the presence of a statedfeature, number, operation, component, element, or combination thereof,but do not preclude the presence or addition of one or more otherfeatures, numbers, operations, components, elements, or combinationsthereof.

The terms used herein, including technical and scientific terms, havethe same meanings as terms that are generally understood by thoseskilled in the art, as long as the terms are not differently defined. Itshould be understood that terms defined in a generally-used dictionaryhave meanings coinciding with those of terms in the related technology.

According to various embodiments of the present disclosure, anelectronic device may include communication functionality. For example,an electronic device may be a smart phone, a tablet personal computer(PC), a mobile phone, a video phone, an e-book reader, a desktop PC, alaptop PC, a netbook PC, a personal digital assistant (PDA), a portablemultimedia player (PMP), a Moving Picture Experts Group phase 2 (MPEG-2)audio layer 3 (MP3) player, a mobile medical device, a camera, awearable device (e.g., a head-mounted device (HMD), electronic clothes,electronic braces, an electronic necklace, an electronic appcessory, anelectronic tattoo, or a smart watch), and/or the like.

According to various embodiments of the present disclosure, anelectronic device may be a smart home appliance with communicationfunctionality. A smart home appliance may be, for example, a television(TV), a digital versatile disc (DVD) player, an audio, a refrigerator,an air conditioner, a vacuum cleaner, an oven, a microwave oven, awasher, a dryer, an air purifier, a set-top box, a TV box (e.g., SamsungHomeSync™, Apple TV™, or Google TV™), a gaming console, an electronicdictionary, an electronic key, a camcorder, an electronic picture frame,and/or the like.

According to various embodiments of the present disclosure, anelectronic device may be a medical device (e.g., magnetic resonanceangiography (MRA) device, a magnetic resonance imaging (MRI) device,computed tomography (CT) device, an imaging device, or an ultrasonicdevice), a navigation device, a global positioning system (GPS)receiver, an event data recorder (EDR), a flight data recorder (FDR), anautomotive infotainment device, a naval electronic device (e.g., navalnavigation device, gyroscope, or compass), an avionic electronic device,a security device, an industrial or consumer robot, and/or the like.

According to various embodiments of the present disclosure, anelectronic device may be furniture, part of a building/structure, anelectronic board, electronic signature receiving device, a projector,various measuring devices (e.g., water, electricity, gas orelectro-magnetic wave measuring devices), and/or the like that includecommunication functionality.

According to various embodiments of the present disclosure, anelectronic device may be any combination of the foregoing devices. Inaddition, it will be apparent to one having ordinary skill in the artthat an electronic device according to various embodiments of thepresent disclosure is not limited to the foregoing devices.

According to various embodiments of the present disclosure, for example,a terminal may be an electronic device.

According to various embodiments of the present disclosure, atransmitting apparatus may be a service provider or a terminal.

According to various embodiments of the present disclosure, a receivingapparatus may be a terminal or a service provider.

According to various embodiments of the present disclosure, atransmitting and receiving apparatus may be a terminal or a serviceprovider.

In various embodiments of the present disclosure, it will be noted thatthe term terminal may be interchangeable with the term mobile station(MS), wireless terminal, mobile device, user equipment (UE), and/or thelike.

An embodiment of the present disclosure proposes an apparatus and methodfor transmitting and receiving a signal in a multimedia system.

An embodiment of the present disclosure proposes an apparatus and methodfor transmitting and receiving a signal in a multimedia systemsupporting a link layer protocol.

An embodiment of the present disclosure proposes an apparatus and methodfor transmitting and receiving information related to a sub-streamincluded in a link layer packet in a multimedia system supporting a linklayer protocol.

An embodiment of the present disclosure proposes an apparatus and methodfor transmitting and receiving information related to a link layerpacket carrying a plurality of sub-streams in a multimedia systemsupporting a link layer protocol.

An embodiment of the present disclosure proposes an apparatus and methodfor effectively transmitting and receiving various types of services ina multimedia system supporting a link layer protocol.

An embodiment of the present disclosure proposes an apparatus and methodfor filtering a sub-stream in a link layer packet in a multimedia systemsupporting a link layer protocol.

An apparatus and method proposed in an embodiment of the presentdisclosure may be applied to various communication systems such as adigital video broadcasting system such as a mobile broadcasting servicesuch as a digital multimedia broadcasting (DMB) service, a digital videobroadcasting-handheld (DVB-H) service, an advanced television systemscommittee-mobile/handheld (ATSC-M/H) service, and the like, and anInternet protocol television (IPTV) service, a moving picture expertsgroup (MPEG) media transport (MMT) system, an evolved packet system(EPS), a long term evolution (LTE) mobile communication system, anLTE-advanced (LTE-A) mobile communication system, a high speed downlinkpacket access (HSDPA) mobile communication system, a high speed uplinkpacket access (HSUPA) mobile communication system, a high rate packetdata (HRPD) mobile communication system proposed in a 3^(rd) generationpartnership project 2 (3GPP2), a wideband code division multiple access(WCDMA) mobile communication system proposed in the 3GPP2, a codedivision multiple access (CDMA) mobile communication system proposed inthe 3GPP2, an Institute of Electrical and Electronics Engineers (IEEE)mobile communication system, a mobile Internet protocol (mobile IP)system, and/or the like.

An apparatus and method proposed in an embodiment of the presentdisclosure may be applied to an advanced television systems committee(ATSC) system which is based on an MMT scheme.

For convenience, in various embodiments of the present disclosure, itwill be assumed that a multimedia system is based on an MMT scheme.

A system architecture of a multimedia system according to an embodimentof the present disclosure will be described with reference to FIG. 1.

FIG. 1 schematically illustrates a system architecture of a multimediasystem according to an embodiment of the present disclosure.

Referring to FIG. 1, a service includes media data 1000 and a signaling1050 for transmitting information required for a receiving apparatus toacquire and consume the media data 1000. For example, the receivingapparatus may be a terminal. The media data 1000 may be encapsulatedinto a format suitable for transport. For example, an encapsulationscheme for the media data 1000 may follow a media processing unit (MPU)format defined in an International Organization for Standardization(ISO)/International Electrotechnical Committee (IEC) 23008-1 MPEG mediatransport (MMT) protocol or a dynamic adaptive streaming over hypertexttransfer protocol (MPEG-DASH) segment format defined in an ISO/IEC23009-1 DASH.

The media data 1000 and the signaling 1050 are packetized by anapplication layer protocol.

A case that an MMT protocol (MMTP) 1110 defined in an MMT scheme and areal-time object delivery over unidirectional transport (ROUTE) protocol1120 are used as the application layer protocol is illustrated inFIG. 1. At this time, in order for a receiving apparatus to know that aservice is transported based on which application layer protocol, amethod for informing information on an application layer protocol thatthe service is transported is required, independently from theapplication layer protocol.

A service list table (SLT) illustrated in FIG. 1 is a signaling schemeused for informing information on an application layer protocol that aservice is transported, configures information on a service as a tableformat, and packetizes the table. An SLT will be described below, so adetailed description thereof will be omitted herein.

Referring to FIG. 1, a signaling including the packetized media data andthe SLT 1150 is output to a broadcast link layer 1400 after passing auser datagram protocol (UDP) 1200 and an Internet protocol (IP) 1300. Anexample of a broadcast link layer may be an ATSC link-layer protocol(ALP) defined in ATSC 3.0. The ALP generates an ALP packet based on aninput IP packet to output the ALP packet to a broadcast physical layer1500.

It will be noted that the broadcast link layer 1400 may use anMPEG-2-transport stream (TS) packet or packetized data which has ageneral format as well as the IP packet including the media data or thesignaling as input. At this time, signaling information required forcontrolling the broadcast link layer 1400 is output to the broadcastphysical layer 1500. Here, a format of the signaling information is anALP packet.

The broadcast physical layer 1500 generates a physical layer frame basedon an input ALP packet, converts the physical layer frame into a radiosignal, and transmits the radio signal. The broadcast physical layer1500 has at least one signal processing path. An example of the signalprocessing path may be a physical layer pipe (PLP) defined in a digitalvideo broadcasting (DVB)-terrestrial version 2 (DVB-T2) or ATSC 3.0, andall of one or more services or a part of a service may be mapped to thePLP. Here, all of the one or more services or the part of the servicemapped to the PLP will be referred to as sub-stream.

A system architecture of a multimedia system according to an embodimentof the present disclosure has been described with reference to FIG. 1,and an architecture of a broadcast link layer of a multimedia systemaccording to an embodiment of the present disclosure will be describedwith reference to FIG. 2.

FIG. 2 schematically illustrates an architecture of a broadcast linklayer of a multimedia system according to an embodiment of the presentdisclosure.

Referring to FIG. 2, input data of a broadcast link layer 1400 includesan IP packet 1315, and may further include a link layer signaling 1310,an MPEG-2-TS packet 1320, and one or more future extensions 1330. Thefuture extension 1330 indicates other packet types which may be input atthe broadcast link layer 1400, e.g., an ALP layer, and protocols. Theinput data may pass an additional processing process according to a typeof the input data before an encapsulation process 1450. For example, ifthe input data is the IP packet 1315, the additional processing processmay be an IP header compression process 1410. If the input data is theMPEG-2-TS packet 1320, the additional processing process may be anoverhead reduction process 1420.

In the encapsulation process 1450, the input data may pass a segmentprocess or a concatenation process.

After the encapsulation process 1450 has been completed, a link layerpacket stream is generated, and the link layer packet stream istransferred to a broadcast physical layer 1500. Here, the link layerpacket stream includes at least one link layer packet.

An architecture of a broadcast link layer of a multimedia systemaccording to an embodiment of the present disclosure has been describedwith reference to FIG. 2, and a format of an ALP packet in a multimediasystem according to an embodiment of the present disclosure will bedescribed with reference to FIG. 3.

FIG. 3 schematically illustrates a format of an ALP packet in amultimedia system according to an embodiment of the present disclosure.

Referring to FIG. 3, an ALP packet includes a header 3100 and a payload3200.

The header 3100 may include a base header 3110, an additional header3120, and an optional header 3130. Whether the additional header 3120 isincluded in the header 3100 may vary according to a value of a controlvalue included in the base header 3110.

Whether to include the optional header 3130 into the ALP packet header3100 may be selected using a control field included in the additionalheader 3120.

A format of an ALP packet in a multimedia system according to anembodiment of the present disclosure has been described with referenceto FIG. 3, and a format of a base header included in an ALP packet in amultimedia system according to an embodiment of the present disclosurewill be described with reference to FIG. 4.

FIG. 4 schematically illustrates a format of a base header included inan ALP packet in a multimedia system according to an embodiment of thepresent disclosure.

Referring to FIG. 4, a base header 3110 (shown in FIG. 3) includes apacket type (Packet_Type) field 4100. At this time, configuration forother fields may vary according to a value of the Packet_Type field4100, and it will be noted that configuration of fields included in thebase header 3110 is configuration of fields used in a case that an inputpacket is at least one of an IP version 4 (IPv4) packet, a compressed IPpacket, a link layer signaling packet, and an extension packet.

The base header 3110 further includes a payload_configuration (PC) field4200. A 1-bit field may be present after the PC field 4200, and meaningof the 1-bit field may vary according to a value of the PC field 4200.

For example, if the value of the PC field 4200 is 0, the 1-bit fieldwhich is present after the PC field 4200 may be a header mode (HM) field4300, and the HM field 4300 indicates whether an additional header 3120is present at an ALP packet 3100. For another example, if the value ofthe PC field 4200 is 1, the 1-bit field which is present after the PCfield 4200 may be a segmentation/concatenation (S/C) field 4350, and theS/C field 4350 indicates whether the payload 3200 includes a pluralityof input packets or a part of an input packet. Configuration of anadditional header 3120 may vary according to a value of the S/C field4350.

The base header 3110 includes a length field 4400 indicating leastsignificant bit (LSB) 11 bits of a length of the payload 3200.

Meanwhile, a base header illustrated in FIG. 4 may be expressed as Table1.

TABLE 1 Num- ber of Mne- Syntax bits monic ALP_Packet_Header( ) {Packet_Type 3 uimsbf Payload_Configuration 1 bslbf if(Payload_Configuration ==“0”){ Header_Mode 1 bslbf Length 11  uimsbf if(Header_Mode ==“1”){ Additional_Header_for_Single_Packet( ) var } } elseif (Payload_Config ==“1”){ Segmentation_Concatenation 1 bslbf Length 11 uimsbf if (Segmentation_Concatenation ==“0”){Additional_Header_for_Segmentation( ) var } else if(Segmentation_Concatenation ==“1”){ Additional_Header_for_Concatenation() var } } }

In Table 1, a Packet_Type field indicates a protocol or a packet type ofan input packet before being encapsulated into an ALP packet. Forexample, the Packet_Type field may be implemented with a 3-bit field.

A value of the Packet_Type field may have meaning as shown in Table 2.

TABLE 2 Packet_Type Value Meaning 000 IPv4 packet 001 Compressed IPpacket 100 MPEG-2 Transport Stream 011 Reserved 100 Link layer signalingpacket 101 Reserved 110 Reserved 111 Packet Type Extension

For example, in Table 2, if a value of the Packet_Type field is ‘000’,it means that a packet type is an IPv4 packet, if a value of thePacket_Type field is ‘001’, it means that a packet type is a compressedIP packet, if a value of the Packet_Type field is ‘010’, it means that apacket type is an MPEG-2 Transport Stream (TS), if a value of thePacket_Type field is ‘011’, it means that the Packet_Type field isreserved for future use, if a value of the Packet_Type field is ‘100’,it means that an input packet is a link layer signaling packet, if avalue of the Packet_Type field is ‘100’ or ‘110’, it means that thePacket_Type field is reserved for future use, and if a value of thePacket_Type field is ‘111’, it means that an input packet is an packettype extension.

In Table 1, for example, a Payload_Configuration field may correspond toa PC field 4200, and indicates configuration of a payload, e.g., apayload 3200. For example, the Payload_Configuration field may beimplemented with a 1-bit field. For example, if a value of thePayload_Configuration field, e.g., the PC field 4200 is 0, the payload3200 includes only one whole input packet, and an HM field 4300 ispresent after the PC field 4200. For another example, if the value ofthe PC field 4200 is 1, the payload 3200 may include a plurality ofwhole input packets or a part of one input packet, and an S/C field 4350is present after the PC field 4200.

In Table 1, a Header_Mode field indicates whether an additional headeris present. For example, the Header_Mode field may be implemented with a1-bit field. If a value of the Header_Mode field, e.g., an HM field 4300is 0, it means that there is no additional header, and it means that alength of a payload 3200 is less than a preset length, e.g., 2048 bytes.If a value of the HM field 4300 is 1, it means that an additional headeris present after a Length field 4400, and the length of the payload 3200is greater than 2047 bytes or an optional header 3130 including asub-stream identifier (SID) is present. The HM field 4300 may be presentonly if the value of the PC field 4200 is 0.

In Table 1, a Segmentation_Concatenation field indicates whether apayload, e.g., a payload 3200 includes a plurality of complete inputpackets or a part of an input packet. For example, theSegmentation_Concatenation field may be implemented with a 1-bit field.If a value of the Segmentation_Concatenation field, e.g., an S/C field4350 is 0, the payload 3200 includes a part of one input packet, andincludes an additional field 3120 defined for packet segment after aLength field 4400. If the value of the S/C field 4350 is 1, the payload3200 includes a plurality of complete input packets, and includes anadditional header 3120 defined for packet concatenation after the Lengthfield 4400. The S/C field 4350 may be present only if the value of thePC field 4200 is 1.

In Table 1, a Length field indicates a length of a payload field, e.g.,a payload 3200 (shown in FIG. 3). For example, the Length fieldindicates LSB 11 bits of a length in bytes of the payload 3200. If theadditional header 3120 includes most significant bit (MSB) bits of thelength in bytes of the payload 3200, the LSB 11 bits are combined withthe MSB bits thereby indicating a total length of the payload 3200.

A format of a base header included in an ALP packet in a multimediasystem according to an embodiment of the present disclosure has beendescribed with reference to FIG. 4, and a format of an additional headerin a case that a payload includes a single input packet in a multimediasystem according to an embodiment of the present disclosure will bedescribed with reference to FIG. 5.

FIG. 5 schematically illustrates a format of an additional header in acase that a payload includes a single input packet in a multimediasystem according to an embodiment of the present disclosure.

Referring to FIG. 5, it will be noted that a format of an additionalheader 5000 illustrated in FIG. 5 is a format of an additional header ina case that a payload, e.g., a payload 3200 includes a single inputpacket.

The additional header 5000 includes a Length_MSB field 5100 indicatingMSB 5 bits in a case that a length in bytes of the payload 3200 isexpressed with 16 bits, a reserved (R) field 5200, a sub-streamidentifier flag (SIF) field 5300 indicating whether a sub-streamidentifier is present, and a header extension flag (HEF) field 5400indicating whether a header extension is present. For example, the Rfield 5200 may be implemented with a 1-bit field.

According to an embodiment of the present disclosure in FIG. 4, theadditional header 5000 in FIG. 5 may be present only if the payload 3200included in an ALP packet includes one complete packet, and a length ofthe one complete packet is greater than a preset length, e.g., 2047bytes or an optional header is present. That is, the additional header5000 may be present only if a value of a PC field 4200 is 0 and a valueof an HM field 4300 is 1.

Meanwhile, the additional header 5000 in FIG. 5 may be expressed asTable 3.

TABLE 3 Num- ber of Mne- Syntax bits monicAdditional_Header_for_Long_Packet ( ) { Length_MSB 5 uimsbf reserved 1bslbf SIF 1 bslbf HEF 1 bslbf if (SIF ==“1”){ SID 8 bslbf } if (HEF==“1”){ Header_Extension( ) var } }

In Table 3, a Length_MSB field indicates MSB 5 bits of a length in bytesof the payload 3200 if a length in bytes of a payload, e.g., the payload3200 is expressed with 16 bits. The MSB 5 bits are combined with LSB 11bits indicated by a Length field 4400 included in a base header 3110thereby indicating a total length of the payload 3200.

In Table 3, an SIF field indicates whether a sub-stream identifier (SID)is present after an HEF field 5400. For example, the SIF field may beimplemented with a 1-bit field. For example, if a value of the SIFfield, e.g., an SIF field 5300 is 0, there is no SID field. If the valueof the SIF field 5300 is 1, the SID field is present after the HEF field5400.

In Table 3, an HEF field indicates whether a header extension is presentafter the additional header 5000. For example, the HEF field may beimplemented with a 1-bit field. For example, if a value of an HEF field5400 is 0, there is no header extension. If the value of the HEF field5400 is 1, the header extension is present after the additional header5000. In a case that the header extension is present, the headerextension is present after the SID field if the SID field is present,and the header extension is present after the HEF field 5400 if there isno SID field.

In Table 3, an SID field indicates an SID for an ALP packet. Here, anSID may be a service identifier for each of a plurality of services atan ALP stream which carriers the plurality of services.

A format of an additional header in a case that a payload includes asingle input packet in a multimedia system according to an embodiment ofthe present disclosure has been described with reference to FIG. 5, anda format of an additional header in a case that a payload includes apart of a single input packet in a multimedia system according to anembodiment of the present disclosure will be described with reference toFIG. 6.

FIG. 6 schematically illustrates a format of an additional header in acase that a payload includes a part of a single input packet in amultimedia system according to an embodiment of the present disclosure.

Referring to FIG. 6, it will be noted that a format of an additionalheader illustrated in FIG. 6 is a format of an additional header in acase that a payload includes a part of a single input packet.

Referring to FIG. 6, if a payload, e.g., a payload 3200 includes a partof a single input packet, an additional header, e.g., an additionalheader 6000 includes a segment_sequence_number field 6100 indicating anidentifier (ID) of a segmented input packet, a last_segment_indicator(LSI) field 6200 indicating whether the payload 3200 includes the lastsegment of an input packet, an SIF field 6300 indicating whether an SIDis present, and an HET field 6400 indicating whether a header extensionis present.

According to an embodiment of the present disclosure in FIG. 4, theadditional header 6000 in FIG. 6 may be present only if a payload 3200,e.g., a payload 3200 included in an ALP packet includes a part of asingle input packet. That is, the additional header 6000 may be presentonly if a value of a PC field, e.g., a PC field 4200 is 1 and a value ofan S/C field, e.g., an S/C field 4350 is 0.

Meanwhile, the additional header 6000 in FIG. 6 may be expressed asTable 4.

TABLE 4 Num- ber of Mne- Syntax bits monicAdditional_Header_for_Segmentation ( ) { Segment_Sequence_Number 5Last_Segment_Indicator SIF 1 bslbf HEF 1 bslbf if (SIF ==“1”){ SID 8bslbf } if (HEF ==“1”){ Header_Extension( ) var } }

In Table 4, a segment_sequence_number field indicates a number foridentifying a part, i.e., a segment of an input packet included in apayload, e.g., a payload 3200, and may be an integer which is equal toor greater than 0. For example, in a case that the input packet issegmented into a plurality of segments, if the first segment among theplurality of segments is included in the payload 3200, a value of thesegment_sequence_number field 6100 is set to 0. Whenever, the nextsegment of the input packet is transported through an ALP packet, thevalue of the segment_sequence_number field 6100 is incremented by apreset value, e.g., 1.

In Table 4, a last_segment_indicator field indicates whether a payload,e.g., a payload 3200 includes the last segment (or the last byte) of theinput packet, and may be implemented with a 1-bit field. If the payload3200 includes the last segment (or the last byte) of the input packet, avalue of the last_segment_indicator field, e.g., an LSI field 6200 isset to 1. If the payload 3200 does not include the last segment (or thelast byte) of the input packet, the value of the LSI field 6200 is setto 0.

In Table 4, an SIF field indicates whether an SID field is present afteran HEF field, e.g., an HEF field 6400. The SIF field may be implementedwith a 1-bit field. If a value of the SIF field, e.g., an SIF field 6300is 0, there is no SID field. If the value of the SIF field 6300 is 1,the SID field is present after the HEF field 6400.

In Table 4, an HEF field indicates whether a header extension is presentafter an additional header, e.g., an additional header 6000. Forexample, the HEF field may be implemented with a 1-bit field. Forexample, if a value of an HEF field 6400 is 0, there is no headerextension. If the value of the HEF field 6400 is 1, the header extensionis present after the additional header 6000. In a case that the headerextension is present, the header extension is present after the SIDfield if the SID field is present, and the header extension is presentafter the HEF field 6400 if there is no SID field.

A format of an additional header in a case that a payload includes apart of a single input packet in a multimedia system according to anembodiment of the present disclosure has been described with referenceto FIG. 6, and a format of an additional header in a case that a payloadincludes a plurality of input packets in a multimedia system accordingto an embodiment of the present disclosure will be described withreference to FIG. 7.

FIG. 7 schematically illustrates a format of an additional header in acase that a payload includes a plurality of input packets in amultimedia system according to an embodiment of the present disclosure.

Referring to FIG. 7, it will be noted that a format of an additionalheader in FIG. 7 is a format of an additional header in a case that apayload includes a plurality of input packets.

If a payload, e.g., a payload 3200 (shown in FIG. 3) includes aplurality of input packets, an additional header 7000 includes aLength_MSB field 7100 indicating MSB 4 bits of a length in bytes of thepayload 3200 in a case that the length in bytes of the payload 3200 isexpressed with 15 bits, a Count field 7200 indicating the number ofinput packets included in the payload 3200, an HEF field 7300 indicatingwhether a header extension is present, and a Component Length field 7400indicating a length of each input packet.

Meanwhile, the additional header 7000 in FIG. 7 may be expressed asTable 5.

TABLE 5 Num- ber of Mne- Syntax bits monicAdditional_Header_for_Concatenation ( ) { Length_MSB 4 uimsbf Count 3uimsbf HEF 1 bslbf for(i=0; i<Count−1; i++) { Component_Length 12 uimsbf } if (HEF ==“1”){ Header_Extension( ) var } }

In Table 5, a Length_MSB indicates LSB 4 bits of a length in bytes of apayload, e.g., a payload 3200 (shown in FIG. 3) in a case that thelength in bytes of the payload 3200 is expressed 15 bits. The LSB 4 bitsare combined with LSB 11 bits indicated by a Length field 4400 includedin a base header, e.g., a base header 3110 thereby indicating a totallength in bytes of the payload 3200.

In Table 5, a count field indicates the number of input packets includedin the payload 3200. For example, the count field may be implementedwith a 3-bit field. A value of the count field, e.g., a Count field 7200is set to (the number of the input packets included in the payload3200—2).

In Table 5, an HEF field indicates whether a header extension is presentafter an additional header, e.g., an additional header 7000. Forexample, the HEF field may be implemented with a 1-bit field. If a valueof an HEF field, e.g., an HEF field 7300 is 0, there is no headerextension. If the value of the HEF field 7300 is 1, a header extensionis present after the additional header 7000. In a case that there is theheader extension, if an SID field is present, the header extension ispresent after the SID field, and if there is no SID field, the extensionheader is present after the HEF field 7300.

In Table 5, a Component_Length field indicates lengths of input packetsincluded in a payload, e.g., a payload 3200. The lengths of the inputpackets are included in the same order as the input packets included inthe payload 3200 and a length of the last input packet is not included.

A format of an additional header in a case that a payload includes aplurality of input packets in a multimedia system according to anembodiment of the present disclosure has been described with referenceto FIG. 7, and a format of an optional header included in an ALP packetin a multimedia system according to an embodiment of the presentdisclosure will be described with reference to FIG. 8.

FIG. 8 schematically illustrates a format of an optional header includedin an ALP packet in a multimedia system according to an embodiment ofthe present disclosure.

Referring to FIG. 8, an optional header 8000, e.g., an optional header3130 (shown in FIG. 3) may include an SID field 8100 indicating an SIDand a header extension field 8200.

The header extension field 8200 includes an extension type field 8210indicating a type of a header extension, an extension length field 8220indicating a length of an header extension, and an extension value field8230 including contents of extension fields.

A length of the extension value 8230 is given by the extension lengthfield 8220. A receiving apparatus checks a value of the extension typefield 8210, calculates a total length of the header extension field 8200based on the value of the extension type field 8210 if the value of theextension type field 8210 is a value that the receiving apparatus maynot analyze, and removes bytes which correspond to the calculatedlength.

A value of the SID field 8100 is set to a unique value which may beidentified within one radio frequency (RF) signal, and a broadcast linklayer, e.g., a broadcast link layer 1400 may perform link layerfiltering based on the value of the SID field 8100.

For example, it will be assumed that five services are transportedthrough an RF signal which has one signal processing path, e.g., onePLP, and each of the five services are transported using three UDP/IPports. A receiving apparatus recovers link layer packets by processing asignal received through the PLP corresponding to a preset processingscheme. The receiving apparatus recovers packets which correspond tofifteen UDP/IP sessions and outputs the recovered packets to an upperlayer.

A service selected by a terminal uses three UDP/IP sessions, so packetstransported through the fifteen UDP/IP sessions are filtered at an IPlayer, e.g., an IP layer 1300 or a UDP layer, e.g., a UDP layer 1200according to an address thereof. This means that most of packets outputfrom a link layer, e.g., about 80% of packets output from the link layerare unnecessary data at an upper layer, and this decreases systemefficiency.

If the broadcast physical layer 1500, the broadcast link layer 1400, andthe IP layer 1300 are implemented with separate hardware, or if thebroadcast physical layer 1500, the broadcast link layer 1400, and the IPlayer 1300 share an interface with other shared layer, system efficiencymay be significantly decrease due to unnecessary data transmission.

So, an embodiment of the present disclosure allocates a separate SID toeach service, allocates an SID to a link layer packet carrying aservice, processes only a link layer packet with an SID whichcorresponds to a service when the service is selected, and outputs onlythe processed packets to an IP layer thereby increasing systemefficiency.

In an embodiment of the present disclosure, one-to-one mapping between aservice and an SID is described, however, an SID may be freely allocatedaccording to a grouping format of input packets to be grouped within onelink layer stream. Here, the grouping format may be an IP address, a UDPport number, a session identifier (ID) of an application layer protocol,or a combination of the IP address, the UDP port number, the session IDof the application layer protocol. The session ID of the applicationlayer protocol may be a packet_id in an MMTP, or a transport sessionidentifier (TSI) in a ROUTE protocol.

Further, one ALP packet stream may include ALP packets to which an SIDis allocated and ALP packets to which an SID is not allocated. In thiscase, it may be preferred to process the ALP packets to which the SID isnot allocated to output the processed packets to an upper layer, andperform a filtering operation based on the ALP packets to which the SIDis allocated.

In an embodiment of the present disclosure, a value of the SID field8100 may be set to a unique value which may be identified within onePLP. In this case, one sub-stream is identified based on a combinationof a PLP and an SID.

A format of an additional header in a case that a payload includes alink layer signaling in a multimedia system according to an embodimentof the present disclosure will be described with reference to FIG. 9.

FIG. 9 schematically illustrates a format of an additional header in acase that a payload includes a link layer signaling in a multimediasystem according to an embodiment of the present disclosure.

Referring to FIG. 9, it will be noted that a format of an additionalheader 9000 is a format of an additional header in a case that apayload, e.g., a payload 3200 (shown in FIG. 3) includes a link layersignaling.

The additional header 9000 includes a Signaling_Type field 9100indicating a type of the link layer signaling, aSignaling_Type_Extension field 9200 indicating extension information forthe type of the link layer signaling, a Signaling_Version field 9300indicating a version of the link layer signaling, a Signaling_Formatfield 9400 indicating a data format of the link layer signaling, aSignaling_Encoding field 9500 indicating an encoding/compressing schemewhich is applied to the link layer signaling, and a reserved field 9600.For example, the Signaling_Type_Extension field 9200 may be implementedwith a 16-bit field, the Signaling_Version field 9300 may be implementedwith an 8-bit field, the Signaling_Format field 9400 may be implementedwith a 2-bit field, the Signaling_Encoding field 9500 may be implementedwith a 2-bit field, and the reserved field 9600 may be implemented witha 4-bit field.

The additional header 9000 in FIG. 9 may be expressed as shown in Table6.

TABLE 6 Num- ber of Mne- Syntax bits monicAdditional_Header_for_Signaling_information( ) { Signaling_Type 8 uimsbfSignaling_Type_Extension 16 bslbf Signaling_Version 8 uimsbfSignaling_Format 2 uimsbf Signaling_Encoding 2 uimsbf Reserved 4 bslbf }

In Table 6, a Signaling_Type field indicates a type of a link layersignaling included in the payload 3200. For example, the Signaling_Typefield may be implemented with an 8-bit field. If a value of theSignaling_Type field is “0x00”, it means that the type of the link layersignaling included in the payload 3200 is a PLP_Configuration_Table. Ifa value of the Signaling_Type field is “0x01”, it means that the type ofthe link layer signaling included in the payload 3200 is anROHC-U_description_table (RDT). The PLP_Configuration_Table and theROHC-U_description_table will be described below, and a detaileddescription thereof will be omitted herein.

In Table 6, a Signaling_Type_Extension field indicates extensioninformation for the type of the link layer signaling included in thepayload 3200. For example, the Signaling_Type_Extension field may beimplemented with a 16-bit field.

In Table 6, a Signaling_Version field indicates version information ofthe link layer signaling included in the payload 3200. For example, theSignaling_Version field may be implemented with an 8-bit field. A valueof the Signaling_Version field is increased by 1 whenever a version of alink layer signaling identified by the Signaling_Type field is changed.

In Table 6, a Signaling_Format field indicates a data format of the linklayer signaling included in the payload 3200. For example, theSignaling_Format field may be implemented with a 2-bit field. Forexample, the Signaling_Format field may indicate a data format as shownin Table 7.

TABLE 7 Signaling_Format Meaning 00 Binary 01 XML 10 Reserved 11Reserved

In Table 7, if a value of the Signaling_Format field is “00”, it meansthat a data format of the link layer signaling included in the payload3200 is a binary format. In Table 7, if a value of the Signaling_Formatfield is “01”, it means that a data format of the link layer signalingincluded in the payload 3200 is an extensible markup language (XML)format. In Table 7, if a value of the Signaling_Format field is one of“10” and “11”, it means that the value of the Signaling_Format field isreserved for future use.

In Table 7, a Signaling_Encoding field indicates an encoding/compressingscheme applied to the link layer signaling included in the payload 3200.For example, the Signaling_Encoding field may be implemented with a2-bit field. For example, the Signaling_Encoding field may express anencoding/compressing scheme as shown in Table 8.

TABLE 8 Signaling_Encoding Number of bits 00 No Compression 01DEFLATE(RFC1951) 10 Reserved 11 Reserved

In Table 8, if a value of the Signaling_Encoding field is “00”, it meansthat a compressing scheme is not applied to the link layer signalingincluded in the payload 3200. In Table 8, if a value of theSignaling_Encoding field is “01”, it means that a compressing schemeapplied to the link layer signaling included in the payload 3200 is aDEFLATE scheme defined in a request for comments (RFC) 1951. In Table 8,if a value of the Signaling Encoding field is one of “10” and “11”, itmeans that the value of the Signaling_Encoding field is reserved forfuture use.

Meanwhile, some of fields included in an additional field as shown inTable 6 may be omitted according to a scheme of operating a link layerprotocol. Further, other fields may be added into the additional headeras shown in Table 6 according to the scheme of operating the link layerprotocol.

For example, in a case that a data format of a link layer signaling islimited to a binary format or an XML format, a Signaling_Format fieldamong fields included in an additional header as shown in Table 6 may beomitted. For another example, in a case that an encoding/compressingscheme is not applied to a link layer signaling, or a predeterminedscheme is applied to a link layer signaling, a Signaling_Encoding fieldamong the fields included in the additional header as shown in Table 6may be omitted.

In a multimedia system according to an embodiment of the presentdisclosure, it will be assumed that one link layer packet stream isallocated to one PLP. The link layer packet stream may be generatedbased on inputs of various formats as described in FIG. 2.

In an embodiment of the present disclosure, for convenience, it will beassumed that inputs to a broadcast link layer 1400 include a link layersignaling 1310 and an IP packet 1315. In an embodiment of the presentdisclosure, for convenience, it will be assumed that a robust headercompression (ROHC) scheme standardized in an Internet engineering taskforce (IETF) is used as a header compression scheme.

Table 9 shows an example of a link mapping table proposed in amultimedia system according to an embodiment of the present disclosure.

TABLE 9 Num- ber of Mne- Syntax bits monic PLP_Configuration_Table( ) {signaling_type 8 uimsbf PLP_ID 8 uimsbf Num_session 8 uimsbf for(i=0; i<Num_ session; i++) { Src_IP_add 32 uimsbf Dst_IP_add 32 uimsbfSrc_UDP_port 16 uimsbf Dst_UDP_port 16 uimsbf SID_flag 1 bslbfCompressed_flag 1 bslbf reserved 6 ‘000000’ if(SID_flag ==“1”) { SID 8uimsbf } if(Compressed_flag == “1”) { Context_ID 8 uimsbf } } }

In Table 9, a Signaling_type field indicates a type of a signalingcarried by the link mapping table. The link mapping table in Table 9 isa PLP configuration table (PCT), so a value of the Signaling_type fieldmay be set to a value indicating the PCT. In an embodiment of thepresent disclosure, for example, a PCT for each of an IPv4 and IPversion 6 (IPv6) may be defined, and different table_ids may beallocated to the PCTs of the IPv4 and the IPv6. For example, theSignaling_type field may be implemented as an 8-bit field. Here, atable_id denotes an ID of a link mapping table.

In Table 9, a PLP_ID field indicates a PLP ID to which informationincluded in a current PLP is applied. For example, the PLP_ID field maybe implemented as an 8-bit field.

In Table 9, a Num_session field indicates the number of sessions, e.g.UDP/IP sessions, of which information are described in a current table,e.g., a current PCT. For example, the Num_session field may beimplemented as an 8-bit field.

In Table 9, a Src_IP_add field indicates a source IP address of asession carried by the PLP_ID field. For example, the Src_IP_add fieldmay be implemented as a 32-bit field.

In Table 9, a Dst_IP_add field indicates a destination IP address of asession carried by the PLP_ID field. For example, the Dst_IP_add fieldmay be implemented as a 32-bit field.

In Table 9, a Src_UDP_port field indicates a source UDP port number. Forexample, the Src_UDP_port field may be implemented as a 16-bit field.

In Table 9, a Dst_UDP_port field indicates a destination UDP portnumber. For example, the Dst_UDP_port field may be implemented as a16-bit field.

In Table 9, an SID_flag field indicates whether an SID is allocated. Forexample, the SID_flag field may be implemented with a 1-bit field. Forexample, only if a value of the SID_flag field is 1, an SID field isadded to an ALP packet including a UDP/IP packet which is carriedthrough a session.

In Table 9, an SID field indicates an SID. For example, the SID fieldmay be implemented with an 8-bit field. For example, the SID fieldexists only if a value of the SID_flag field is 1. The SID may be avalue which is unique within one RF signal, e.g., a physical layer frameor a PLP.

In Table 9, a Compressed_flag field indicates whether a headercompression scheme is applied, e.g., whether a header compression schemeis applied to an ALP packet carrying the sessions. For example, theCompressed_flag field may be implemented with a 1-bit field. Forexample, if the header compression scheme is applied, a value of theCompressed_flag field is set to 1, and a Context_Id is present after theCompressed_flag field.

In Table 9, a Context_ID field indicates a context ID (CID) foridentifying an IP stream to which a header compression scheme isapplied, and a value of the Context_ID field is generated based on aheader compression standard such as ROHC, and/or the like. TheContext_ID field exists only if the value of the Compressed_flag fieldis 1.

In Table 9, if a UDP/IP stream is used as an input to a link layer, theSrc_IP_add field, the Dst_IP_add field, the Src_Udp_port field, and theDst_Udp_port field are for identifying the UDP/IP stream. So, if apacket which is encapsulated based on other protocol, not an UDP/IP isused as an input to the link layer, it may be understood that theSrc_IP_add field, the Dst_IP_add field, the Src_Udp_port field, and theDst_Udp_port field need to be changed to information suitable for theother protocol.

Table 9 is a link mapping table in a case of assuming a link layerprotocol optionally supporting an SID, whether an SID_flag field and anSID field exist may be varied according to a link layer protocol. If thelink layer protocol does not support an SID, the link mapping table asdescribed in Table 9 does not include an SID_flag field and an SIDfield. If the link layer protocol mandatorily supports an SID, anSID_flag field may be omitted in the link mapping table as described inTable 9. Further, information related to an SID may be transmittedthrough a link mapping table different from a link mapping table throughwhich information related to the header compression is transmitted.

The link mapping table as described in Table 9 is a link mapping tablein a case that the link mapping table is transmitted through a linkmapping protocol optionally supporting header compression on a sessionbasis, and whether the Compressed_flag field and the Context_id fieldexist may be varied according to a link layer protocol.

For example, if the link layer protocol does not support headercompression, a link mapping table does not include the Compressed_flagfield and the Context_id field. For another example, if the link layerprotocol mandatorily supports header compression, the Compressed_flagfield may be omitted in a link mapping table. For still another example,if the link layer protocol supports header compression on a PLP basis,in a link mapping table, the Compressed_flag field may be locatedoutside of a Num_session loop, and the Context_id field may beoptionally located within the Num_session loop according to a value ofthe Compressed_flag field. Further, information related to headercompression may be transmitted through a link mapping table differentfrom a link mapping table through which information related to an SID istransmitted.

It will be assumed that the link mapping table in FIG. 9 describesinformation related to one PLP, and the link mapping table in FIG. 9includes a PLP_ID field for informing information related to a PLP otherthan the PLP through which the link mapping table is transmitted.

If information related to a plurality of PLPs is transmitted using onelink mapping table, a Num_PLP field indicating the number of PLPs ofwhich information is described may be included in a link mapping tableas shown in Table 10. In a case of assuming that each of all linkmapping tables indicates information on a PLP through which a linkmapping table is transmitted, a PLP_ID field may be omitted in a linkmapping table.

TABLE 10 Num- ber of Mne- Syntax bits monic PLP_Configuration_Table( ) {signaling_type 8 uimsbf reserved 2 ‘00’ Num_PLP 6 uimsbffor(i=0;i<Num_PLP;i++) { PLP_ID 8 uimsbf Num_session 8 uimsbf for(j=0;i< Num_ session; i++) { Src_IP_add 32 uimsbf Dst_IP_add 32 uimsbfSrc_UDP_port 16 uimsbf Dst_UDP_port 16 uimsbf SID_flag 1 bslbfCompressed_flag 1 bslbf reserved 6 ‘000000’ if(SID_flag ==“1”) { SID 8uimsbf } if(Compressed_flag == “1”) { Context_ID 8 uimsbf } } } }

The link mapping table as shown in Table 10 further includes a Num_PLPfield including the number of PLPs compared to the link mapping table asshown in Table 9. A Signaling_type field, a PLP_ID field, a Num_sessionfield, a Src_IP_add field, a Dst_IP_add field, a Src_UDP_port field, aDst_UDP_port field, an SID_flag field, an SID field, a Compressed_flagfield, and a Context_ID included in Table 10 are similar to aSignaling_type field, a PLP_ID field, a Num_session field, a Src_IP_addfield, a Dst_IP_add field, a Src_UDP_port field, a Dst_UDP_port field,an SID_flag field, an SID field, a Compressed_flag field, and aContext_ID included in Table 9, so a detailed description thereof willbe omitted herein.

A multimedia system according to an embodiment of the present disclosuremay operate a link mapping table as shown in Table 9 and a link mappingtable as shown in Table 10 together according to a system operatingscheme. For example, different Signaling_type field values are allocatedto the link mapping table as shown in Table 9 and the link mapping tableas shown in Table 10, so two link mapping tables may be operated. Foranother example, the same Signaling_type field value is used for thelink mapping table as shown in Table 9 and the link mapping table asshown in Table 10, and whether a link mapping table is changed, a PLP IDof which information is included in, and/or the like may be indicatedusing a Signaling_Type_Extension field. It will be noted that a schemeof operating a link mapping table as described above is optional, andone of various embodiments of the present disclosure.

In a case that a standardized packet compression scheme such as ROHC,and/or the like is used in a multimedia system according to anembodiment of the present disclosure, a link layer signaling may furtherinclude an additional signaling table following the standardized packetcompression scheme. At this time, a Context_ID field as described inTables 9 and 10 may be used as information for providing a reference forcontext information described in the additional signaling table and aUDP/IP session which is described in the link mapping table in Tables 9and 10.

Table 11 shows an example of header compression information, e.g., anROHC-U_description table in a case that a robust header compressionU-mode (ROHC-U) scheme is used as a header compression algorithm in amultimedia system according to an embodiment of the present disclosure.

TABLE 11 Num- ber of Mne- Syntax bits monic ROHC-U_description_table {signaling_type 8 TBD PLP_ID 8 uimsbf adaptation_mode 2 uimsbfcontext_config 2 bslbf reserved 4 bslbf num_context 8 uimsbffor(i=0;i<num_context;i++) { context_id 8 uimsbf context_profile 8uimsbf if(context_config=0x01) { context_length 8 uimsbfstatic_chain_byte( ) var uimsbf } else if(context_config=0x02) {context_length 8 uimsbf dynamic_chain_byte( ) var uimsbf } elseif(context_config=0x03) { context_length 8 uimsbf static_chain_byte( )var uimsbf dynamic_chain_byte( ) var uimsbf } } }

In Table 11, an adaptation_mode field indicates an adaptation module ofa corresponding PLP. The adaptation_mode field may be implemented with a2-bit field, and a detailed description of the adaptation_mode fieldwill be omitted herein.

In Table 11, a context_config field indicates a combination of thecontext information, and may be implemented with, for example, a 2-bitfield. In Table 11, a num_context field indicates the number of contextswhich are described in the ROHC-U_description table, and may beimplemented with, for example, an 8-bit field.

In Table 11, a context_id field indicates a context ID (CID) of acompressed IP stream, and may be implemented with, for example, an 8-bitfield. In Table 11, a context_profile field indicates a range ofprotocols used for compressing an IP stream, and may be implementedwith, for example, an 8-bit field.

In Table 11, a context_length field indicates a length of a static chainbyte sequence, and may be implemented with, for example, an 8-bit field.In Table 11, a static_chain_byte( ) field indicates static informationused for initializing the ROHC-U decompressor. In Table 11, adynamic_chain_byte( ) field indicates dynamic information used forinitializing the ROHC-U decompressor.

An example of a process of transmitting data in a transmitting apparatusin a multimedia system supporting a link layer protocol according to anembodiment of the present disclosure will be described with reference toFIG. 10.

FIG. 10 schematically illustrates an example of a process oftransmitting data in a transmitting apparatus in a multimedia systemsupporting a link layer protocol according to an embodiment of thepresent disclosure.

Referring to FIG. 10, in a multimedia system according to an embodimentof the present disclosure, a transmitting apparatus provides a serviceusing two PLPs with different reliabilities, e.g., a PLP 1 10500 and aPLP 2 10510. It will be assumed that a reliability of the PLP 1 10500 ishigher than a reliability of the PLP 2 10510. One service is providedusing three MMTP packet sub-flows 10100, 10110, and 10120. The MMTPpacket sub-flows 10100, 10110, and 10120 denote flows of an MMTP packetwhich have the same packet_id. For example, in FIG. 10, it will beassumed that the MMTP packet sub-flow A 10100 includes a service-levelsignaling message, the MMTP packet sub-flow B 10110 includes voice data,and the MMTP packet sub-flow C 10120 includes image data. Theservice-level signaling message includes a list of assets configuring aservice, and a characteristic and an address of each asset. In anembodiment of the present disclosure, the address of the asset includesa packet_id of an MMTP packet including the asset, and may include adestination IP address and a port number of a UDP/IP session throughwhich the MMTP packet is transmitted if necessary. In an embodiment ofthe present disclosure, the address of the asset may include a PLPidentifier (ID) of a PLP through which the MMTP packet is transmitted.

The MMTP packet sub-flow A 10100 and the MMTP packet sub-flow B 10110are multiplexed as an MMTP session 1 10200, and the multiplexed signal,i.e., a UDP/IP packet is transferred to a UDP/IP session 1 10300. TheUDP/IP packet transferred to the UDP/IP session 1 10300 and an outputfrom a Signaling server 10350 are generated as an ALP packet, the ALPpacket is multiplexed as an ALP stream 1 10400, and the ALP stream 110400 is transferred to the PLP 1 10500. The MMTP packet sub-flow C10120 is multiplexed as an MMTP session 2 10210, and the multiplexedsignal, i.e., a UDP/IP packet is transferred to a UDP/IP session 210310. The UDP/IP packet transferred to the UDP/IP session 2 10310 andan output from the Signaling server 10350 are generated as an ALPpacket, the ALP packet is multiplexed as an ALP stream 2 10410, and theALP stream 2 10410 is transferred to the PLP 2 10510. The stream(s) maybe transferred from PLP 1 and/or PLP 2 to physical layer frame (PHYframe) 10600 as shown in FIG. 10.

The output from the Signaling server 10350 includes a signaling table oran UDP/IP packet which is generated by encapsulating a signaling table.The signaling table may be a PCT as described above, and the UDP/IPpacket which is generated by encapsulating the signaling table may be aUDP/IP packet including a low-level signaling (LLS) table of ATSC 3.0.

Table 12 shows an example of the LLS table.

TABLE 12 Syntax No. of Bits Format LLS_table( ) { LLS_table_id 8 uimsbfprovider_id 8 uimsbf LLS_table_version 8 uimsbf switch (LLS_table_id) {case 0x01: SLT var break; case 0x02: RRT var break; case 0x03:SystemTime var break; case 0x04: CAP var break; default: reserved var }}

In Table 12, an SLT denotes a service list table, and indicatesinformation related to a location from which a list of broadcastservices and a service-level signaling for each service may be acquired.The information related to the location from which the service-levelsignaling may be acquired includes a protocol which a transmissionpacket including the service-level signaling follows, an IP address, anda UDP port. In an embodiment of the present disclosure, the informationrelated to the location from which the service-level signaling may beacquired further includes a PLP identifier of a PLP through which thetransmission packet is transmitted.

In FIG. 10, the output from the Signaling server 10350 are transferredto all PLPs, however, the output from the Signaling server 10350 may betransferred to a specific PLP according to a type of a signaling. Forexample, all of the service-level signaling and the output from theSignaling server 10350 may be transferred to one PLP, and if a pluralityof service providers use one RF signal, a signaling is configured foreach service provider, and the configured signalings may be transmittedto different PLPs. For example, a service provider may be a serviceoperator. A signaling table and a UDP/IP which is generated byencapsulating the signaling table among the output of the Signalingserver 10350 may be transmitted through the same PLP or different PLPs.

Although FIG. 10 illustrates an example of a process of transmittingdata in a transmitting apparatus in a multimedia system supporting alink layer protocol according to an embodiment of the presentdisclosure, various changes could be made to FIG. 10. For example,although shown as a series of operations, various operations in FIG. 10could overlap, occur in parallel, occur in a different order, or occurmultiple times.

An example of a process of transmitting data in a transmitting apparatussupporting a link layer protocol in a multimedia system according to anembodiment of the present disclosure has been described with referenceto FIG. 10, and a process of configuring a channel map in a receivingapparatus in a multimedia system supporting a link layer protocolaccording to an embodiment of the present disclosure will be describedwith reference to FIG. 11.

FIG. 11 schematically illustrates a process of configuring a channel mapin a receiving apparatus in a multimedia system supporting a link layerprotocol according to an embodiment of the present disclosure.

Referring to FIG. 11, a receiving apparatus receives an L1 signalingthrough an RF signal at operation 11100. The L1 signaling includesinformation for receiving and processing a PLP which is transmittedthrough the RF signal, e.g., information on a PLP through which an SLTis transmitted. The receiving apparatus acquires a PLP list through theSLT is transmitted by processing the L1 signaling at operation 11200,and processes the PLP through which the SLT is transmitted at operation11300. A result of the PLP processing may be a link layer packetaccording to an embodiment of the present disclosure.

The receiving apparatus acquires a link layer signaling by processing alink layer packet including the link layer signaling among the linklayer packets at operation 11400. The link layer signaling may be a PCTaccording to an embodiment of the present disclosure. The receivingapparatus stores mapping relation between a PLP and a UDP/IP session byanalyzing the link layer signaling at operation 11500.

The receiving apparatus extracts an IP packet by processing a link layerpacket including the IP packet among the link layer packets, andtransfers the IP packet to a UDP/IP processor included in the receivingapparatus. The receiving apparatus acquires an SLT by processing an IPpacket including the SLT among the IP packets at operation 11600. In anembodiment of the present disclosure, the IP packet including the SLTmay be a packet with an IP address for a specific object and adestination UDP port number. The SLT includes information from which aservice layer signaling (SLS) may be acquired per service, and thereceiving apparatus acquires an SLS using the information at operation11700. The receiving apparatus acquires and stores a media transmissionlocation per service by processing the SLS at operation 11800.

Upon detecting that a service is selected from a user after performingthe described process, the receiving apparatus may acquire aservice-level signaling up to a UDP/IP session-level for the selectedservice and a media transmission location based on information providedby an SLT and an SLS. For example, in a case that an MMTP is used, thereceiving apparatus may acquire a destination address, a port number,and a packet_id for identifying an MMTP packet sub-flow included in theMMTP session. The receiving apparatus may acquire the service-levelsignaling and a media transmission location up to a PLP-level based onlocation information up to the UDP/IP session-level and mappinginformation between a UDP/IP session and a PLP provided in a link layersignaling to receive data.

In a multimedia system according to an embodiment of the presentdisclosure, it will be assumed that a link layer signaling and an SLTare transmitted through the same PLP. However, the link layer signalingand the SLT may be transmitted through different PLPs. In an embodimentof the present disclosure, a link layer signaling may be transmittedthrough all PLPs.

In an embodiment of the present disclosure, it will be assumed thatPLP-level location information is transferred through a link layersignaling. However, the PLP-level location information may betransferred through an SLT or an SLS.

Although FIG. 11 illustrates a process of configuring a channel map in areceiving apparatus in a multimedia system supporting a link layerprotocol according to an embodiment of the present disclosure, variouschanges could be made to FIG. 11. For example, although shown as aseries of operations, various operations in FIG. 11 could overlap, occurin parallel, occur in a different order, or occur multiple times.

A process of configuring a channel map in a receiving apparatus in amultimedia system supporting a link layer protocol according to anembodiment of the present disclosure has been described with referenceto FIG. 11, and another example of a process of transmitting data in atransmitting apparatus in a multimedia system supporting a link layerprotocol according to an embodiment of the present disclosure will bedescribed with reference to FIG. 12.

FIG. 12 schematically illustrates another example of a process oftransmitting data in a transmitting apparatus in a multimedia systemsupporting a link layer protocol according to an embodiment of thepresent disclosure.

Referring to FIG. 12, a transmitting apparatus provides a service usingtwo PLPs with different reliabilities, e.g., a PLP 1 10500 and a PLP 210510. It will be assumed that a reliability of the PLP 1 10500 ishigher than a reliability of the PLP 2 10510. One service is providedusing three MMTP packet sub-flows 10100, 10110, and 10120, e.g., an MMTPpacket sub-flow A 10100, an MMTP packet sub-flow B 10110, and an MMTPpacket sub-flow C 10120. An MMTP packet sub-flow denotes a flow of anMMTP packet which have the same packet_id. For example, in FIG. 12, itwill be assumed that the MMTP packet sub-flow A 10100 includes aservice-level signaling message, the MMTP packet sub-flow B 10110includes voice data, and the MMTP packet sub-flow C 10120 includes imagedata. The service-level signaling message includes a list of assetsconfiguring a service, and a characteristic and an address of eachasset. In an embodiment of the present disclosure, the address of theasset includes a packet_id of an MMTP packet including the asset, andmay include a destination IP address and a port number of a UDP/IPsession through which the MMTP packet is transmitted if necessary. In anembodiment of the present disclosure, the address of the asset mayinclude a PLP identifier (ID) of a PLP through which the MMTP packet istransmitted.

Referring to FIG. 12, the MMTP packet sub-flow A 10100, the MMTP packetsub-flow B 10110, and the MMTP packet sub-flow C 10120 are multiplexedas an MMTP session 1 12200, and the MMTP session 1 12200 is transferredto a UDP/IP session 1 12300. The UDP/IP packet transferred to the UDP/IPsession 12300 and the output from the Signaling server 10350 aregenerated as an ALP packet, the ALP packet is de-multiplexed into an ALPstream 1 10400 and an ALP stream 2 10410, and the ALP stream 1 10400 andthe ALP stream 2 10410 are transferred to a PLP 1 10500 and a PLP 210510, respectively.

The de-multiplexing process is performed based on information on aUDP/IP session and MMTP-level information. In an embodiment of thepresent disclosure, the de-multiplexing process is performed based on apacket_id of an MMTP packet. At this time, information related tomapping relation between an MMTP packet and an ALP_stream, i.e., mappingrelation between a packet_id and an ALP_stream may be transferredthrough an additional information transfer process. In an embodiment ofthe present disclosure, the de-multiplexing may be performed through IPtunneling between an MMPT output device and a de-multiplexer. At thistime, the MMPT output device transfers an MMTP packet to be mapped to anALP stream 1 and an MMTP packet to be mapped to an ALP stream 2 to thede-multiplexer through additional IP tunnels. At this time, informationrelated to mapping relation between an IP packet and an ALP_stream,i.e., mapping relation between an IP tunnel and an ALP_stream may betransferred through an additional information transfer process.

The output from the Signaling server 10350 includes a signaling table oran UDP/IP packet which is generated by encapsulating the signalingtable. The signaling table may be a PCT as described above, and theUDP/IP packet which is generated by encapsulating the signaling tablemay be a UDP/IP packet including an LLS table of ATSC 3.0. A PCTaccording to an embodiment of the present disclosure may be expressed asTable 13.

TABLE 13 Num- ber of Mne- Syntax bits monic PLP_Configuration_Table( ) {signaling_type 8 uimsbf Reserved 2 ‘00’ Num_PLP 6 uimsbffor(i=0;i<Num_PLP;i++) { PLP_ID 8 uimsbf Num_session 8 uimsbf for(j=0;i< Num_session; i++) { Src_IP_add 32 uimsbf Dst_IP_add 32 uimsbfSrc_UDP_port 16 uimsbf Dst_UDP_port 16 uimsbf Protocol_id 8 uimsbfswitch (Protocol_id) { case 0x01: num_sub_flow 32 uimsbffor(k=0;k<num_sub_flow) { Tsi 32 uimsbf } break; case: 0x02:num_sub_flow 16 uimsbf for(k=0;k<num_sub_flow) { packet_id 16 uimsbf {break; default: reserved var } } } }

In Table 13, a Protocol_id field may be expressed as Table 14.

TABLE 14 Protocol Meaning 0 Reserved 1 ROUTE 2 MMTP other valuesReserved for future use

If a value of the Protocol_id field is “1”, it means that acorresponding protocol is a ROUTE, and if a value of the Protocol_idfield is “2”, it means that a corresponding protocol is an MMTP.

If the Protocol_id field is expressed as Table 14, a tsi in Table 13indicates an identifier (ID) of an LCT channel configuring a ROUTEsession, and a packet_id indicates an ID of an MMTP packet sub-flowconfiguring an MMTP session.

In an embodiment of the present disclosure, the PCT may be expressed asshown in Table 15.

TABLE 15 Num- ber of Mne- Syntax bits monic PLP_Configuration_Table( ) {signaling_type 8 uimsbf Reserved 2 ‘00’ Num_PLP 6 uimsbffor(i=0;i<Num_PLP;i++) { PLP_ID 8 uimsbf Num_session 8 uimsbf for(j=0;i< Num_session; i++) { Src_IP_add 32 uimsbf Dst_IP_add 32 uimsbfSrc_UDP_port 16 uimsbf Dst_UDP_port 16 uimsbf Protocol_type 8 uimsbfswitch (Protocol_type) { case 0x01: num_sub_flow 8 uimsbffor(k=0;k<num_sub_flow) { sub_flow_id 8 uimsbf } break; case: 0x02:num_sub_flow 16 uimsbf for(k=0;k<num_sub_flow) { sub_flow_id 16 Uimsbf }break; case: 0x04: num_sub_flow 32 uimsbf for(k=0;k<num_sub_flow) {sub_flow_id 32 uimsbf } break; } }

In Table 15, a Protocol_type field indicates an identifier (ID) used foridentifying a sub-flow in a general upper layer protocol, and indicates,for example, a length in bytes.

In FIG. 12, the output from the Signaling server 10350 is transferred toall PLPs, however, the output from the Signaling server 10350 may betransferred to a specific PLP according to a type of a signaling. Forexample, all of the service-level signaling and the output from theSignaling server 10350 may be transferred to one PLP, and if a pluralityof service providers use one RF signal, a signaling is configured foreach service provider, and the configured signalings may be transmittedto different PLPs. A signaling table and a UDP/IP which is generated byencapsulating the signaling table among the output of the Signalingserver 10350 may be transmitted through the same PLP or different PLPs.

A receiving apparatus which receives a signal transmitted as describedin FIG. 12 may configure a channel map based on a process similar to aprocess as described in FIG. 11. At this time, information related to alocation at a PLP-level may be includes in an SLT/SLS, a PCT, or both anSLT/SLS and a PCT.

Although FIG. 12 illustrates another example of a process oftransmitting data in a transmitting apparatus in a multimedia systemsupporting a link layer protocol according to an embodiment of thepresent disclosure, various changes could be made to FIG. 12. Forexample, although shown as a series of operations, various operations inFIG. 12 could overlap, occur in parallel, occur in a different order, oroccur multiple times.

Another example of a process of transmitting data in a transmittingapparatus in a multimedia system supporting a link layer protocolaccording to an embodiment of the present disclosure has been describedwith reference to FIG. 12, and a process of compressing a UDP/IP headerin a multimedia system supporting a link layer protocol according to anembodiment of the present disclosure will be described with reference toFIG. 13.

FIG. 13 schematically illustrates a process of compressing a UDP/IPheader in a multimedia system supporting a link layer protocol accordingto an embodiment of the present disclosure.

Referring to FIG. 13, IP packets output from a UDP/IP layer 13100included in a transmitting apparatus are encapsulated into an ALP packetin which a UDP/IP header is compressed in a link layer 13200 included inthe transmitting apparatus, and the ALP packet is transferred to aphysical layer 13300 included in the transmitting apparatus. At thistime, information required for recovering the compressed UDP/IP headermay be encapsulated into an additional ALP packet. The physical layer13300 included in the transmitting apparatus converts input ALP packetsinto an RF signal to transmit the RF signal.

The RF signal transmitted in the physical layer 13300 included in thetransmitting apparatus is transferred to a physical layer 13400 includedin a receiving apparatus. The physical layer 13400 included in areceiving apparatus extracts an ALP packet from the received RF signalto transfer the extracted ALP packet to a link layer 13500 included inthe receiving apparatus. The link layer 13500 included in the receivingapparatus extracts a UDP/IP packet from the ALP packet to transfer theUDP/IP packet to a UDP/IP layer 13600 included in the receivingapparatus.

Meanwhile, a process of compressing a UDP/IP header performed in thelink layer 13200 included in the transmitting apparatus will bedescribed below.

A UDP/IP header included in a UDP/IP packet output from the UDP/IP layer13100 included in the transmitting apparatus is compressed in an ROHCmodule 13210 included in the transmitting apparatus. The compressedUDP/IP header includes information for recovering the UDP/IP header inthe receiving apparatus. The information for recovering the UDP/IPheader includes a Context ID (CID), a static chain, and a dynamic chain.The ROHC module 13210 included in the transmitting apparatus inputs IPpackets corresponding to one or more UDP/IP sessions, and compresses theIP packets to output the compressed one or more packet flows. If theROHC module 13210 included in the transmitting apparatus generates aplurality of compressed packet flows, each of the plurality ofcompressed packet flows may be identified based on a CID of a compressedpacket header. Here, a UDP/IP session may be mapped to a compressedpacket flow one-to-one.

Meanwhile, an adaptation module 13220 included in the transmittingapparatus may configure an additional link layer signaling by extractingat least one of a static chain and a dynamic chain from a compressedUDP/IP header included in a packet included in the compressed packetflow from the ROHC module 13210, and the extracted information may bedeleted from the compressed UDP/IP header. The link layer signaling mayfollow an ROHC-U_description_table (RDT) format as described in Table11. That is, the header of the compressed UDP/IP packet output from theadaptation module 13220 included in the transmitting apparatus may havea format different from a format of a header of a corresponding inputpacket. An encapsulation module 13230 included in the transmittingapparatus encapsulates a packet output from the adaptation module 13220into an ALP packet. A value of a Packet_Type field included in a headerof the ALP packet is encoded thereby the value of a Packet_Type fieldmay be set to a value corresponding to a payload format of the ALPpacket. In a case that an encoding scheme as described in Table 2 isused, a value of the Packet_Type field may be set to ‘001’ if a payloadof an ALP packet includes a compressed UDP/IP packet, and may be set to‘100’ if a payload of an ALP packet includes a link layer signaling.

A process of recovering a UDP/IP header performed in the link layer13500 included in the receiving apparatus will be described below.

A decapsulation module 13530 included in the receiving apparatusextracts data from a payload included in an ALP packet output from thephysical layer 13400 included in the receiving apparatus. A value of aPacket_Type field included in a header of the ALP packet may be variedaccording to a payload format of the ALP packet. In a case that theencoding scheme as described in Table 2 is used, if a value of thePacket_Type field is ‘001’, it means that a payload of an ALP packet isa compressed UDP/IP packet, and if a value of the Packet_Type field is‘100’, it means that a payload of an ALP packet is a link layersignaling. The adaptation module 13520 included in the receivingapparatus performs the reverse of a process performed in the adaptationmodule 13220 included in the transmitting apparatus based on an inputUDP/IP packet and link layer signaling. The reverse process may includea process of recovering an original header from a compressed UDP/IPheader in which at least one of a static chain and a dynamic chain isdeleted based on the static chain and the dynamic chain of the linklayer signaling. If there is no error on a channel, an output from theROHC module 13210 included in the transmitting apparatus is identical toan input to the ROHC module 13510 included in the receiving apparatus.In an embodiment of the present disclosure, the adaptation module 13520included in the receiving apparatus may extract information required forrecovery from a link layer signaling without completely recoveringoutput from the ROHC module 13210 included in the transmittingapparatus, and transfer the extracted information to the ROHC module13510 included in the receiving apparatus.

Although FIG. 13 illustrates a process of compressing a UDP/IP header ina multimedia system supporting a link layer protocol according to anembodiment of the present disclosure, various changes could be made toFIG. 13. For example, although shown as a series of operations, variousoperations in FIG. 13 could overlap, occur in parallel, occur in adifferent order, or occur multiple times.

A process of compressing a UDP/IP header in a multimedia systemsupporting a link layer protocol according to an embodiment of thepresent disclosure has been described with reference to FIG. 13, and aprocess of recovering a UDP/IP header in a receiving apparatus in amultimedia system supporting a link layer protocol according to anembodiment of the present disclosure will be described with reference toFIG. 14.

FIG. 14 schematically illustrates a process of recovering a UDP/IPheader in a receiving apparatus in a multimedia system supporting a linklayer protocol according to an embodiment of the present disclosure.

Referring to FIG. 14, it will be assumed that information related to amedia transmission location for service presentation is acquired andstored based on a process as described in FIG. 11. For example, it willbe assumed that a receiving apparatus has the following information.

(1) Information related to a UDP/IP session through a media istransmitted

(2) PLP identifier of a PLP through a UDP/IP session is transmitted

(3) Sub-stream identifier of a sub-stream corresponding to a UDP/IPsession

(4) CID corresponding to a UDP/IP session

The sub-stream identifier (SID) of the sub-stream corresponding to theUDP/IP session may be optionally allocated, and the CID corresponding tothe UDP/IP session be optionally allocated if a compression scheme isapplied to a UDP/IP header. In FIG. 14, it will be assumed that a headercompression scheme is applied to all UDP/IP sessions.

Firstly, a receiving apparatus detects that a user selects a service atoperation 14100. The receiving apparatus processes a PLP through theservice is transmitted at operation 14200. The receiving apparatusextracts an ALP packet at operation 14300. As described above, theextracted ALP packet includes a compressed UDP/IP packet or a link layersignaling as a payload. The receiving apparatus determines whether theALP packet includes a link layer signaling at operation 14400. Here,whether the ALP packet includes the link layer signaling may bedetermined based on a value of a Packet_Type field included in the ALPpacket header.

If the ALP packet includes the link layer signaling, the receivingapparatus extracts a link layer signaling included in the ALP packet,i.e., a link layer signaling included in the payload included in the ALPpacket at operation 14450.

If the ALP packet does not include the link layer signaling, thereceiving apparatus proceeds to operation 14500. Here, a case that theALP packet does not include the link layer signaling means that thepayload included in the ALP packet includes a compressed UDP/IP packet.So, the receiving apparatus determines whether there is a UDP/IP sessionunnecessary for service presentation at operation 14500. If there is theUDP/IP session unnecessary for the service presentation, the receivingapparatus discards ALP packets with a sub-stream identifier (SID) whichcorresponds to the UDP/IP session unnecessary for the servicepresentation at operation 14550.

If there is no UDP/IP session unnecessary for the service presentation,the receiving apparatus performs an adaptation operation on the payloadextracted from the ALP packet at operation 14600. Here, a header of thecompressed UDP/IP packet after the adaptation operation includes a CID.The receiving apparatus determines whether the CID is a CID necessaryfor the service presentation at operation 14700. If the CID is a CIDwhich corresponds to a UDP/IP session unnecessary for the servicepresentation, the receiving apparatus discards packets with a CID whichcorresponds to the UDP/IP session unnecessary for the servicepresentation at operation 14750.

If the CID is the CID which corresponds to the UDP/IP session necessaryfor the service presentation, the receiving apparatus performs an ROHCdecompression operation on packets with a CID which corresponds to theUDP/IP session necessary for the service presentation at operation14800. The receiving apparatus transfers a recovered packet after theROHC decompression operation to a UDP/IP layer at operation 14900.

Although FIG. 14 illustrates a process of recovering a UDP/IP header ina receiving apparatus in a multimedia system supporting a link layerprotocol according to an embodiment of the present disclosure, variouschanges could be made to FIG. 14. For example, although shown as aseries of operations, various operations in FIG. 14 could overlap, occurin parallel, occur in a different order, or occur multiple times.

As described above, according to various embodiments of the presentdisclosure, data processing efficiency may be increased by filtering apacket in a link layer.

A process of recovering a UDP/IP header in a receiving apparatus in amultimedia system supporting a link layer protocol according to anembodiment of the present disclosure has been described with referenceto FIG. 14, and an inner structure of a transmitting apparatus in amultimedia system according to an embodiment of the present disclosurewill be described with reference to FIG. 15.

FIG. 15 schematically illustrates an inner structure of a transmittingapparatus in a multimedia system according to an embodiment of thepresent disclosure.

Referring to FIG. 15, a transmitting apparatus 1500 may be a serviceprovider, and/or the like.

The transmitting apparatus 1500 includes a transmitter 1511, acontroller 1513, a receiver 1515, a storage (memory) unit 1517, and anoutput unit 1519. The controller 1513 includes at least one processor.

The controller 1513 controls the overall operation of the transmittingapparatus 1500. More particularly, the controller 1513 controls anoperation related to an operation of transmitting and receiving a signalin a multimedia system according to an embodiment of the presentdisclosure, e.g., an operation of transmitting and receiving informationrelated to a link layer packet carrying a plurality of sub-streams. Theoperation related to the operation of transmitting and receiving theinformation related to the link layer packet carrying the plurality ofsub-streams has been described with reference to FIGS. 1 to 14 andTables 1 to 15, and a detailed description thereof will be omittedherein.

The transmitter 1511 transmits various signals and various messages toother entities, e.g., a receiving apparatus and the like included in themultimedia system under a control of the controller 1513. For example,the receiving apparatus may be a terminal and/or the like. The varioussignals and various messages transmitted in the transmitter 1511 havebeen described with reference to FIGS. 1 to 14 and Tables 1 to 15, and adetailed description thereof will be omitted herein.

The receiver 1515 receives various signals and various messages fromother entities, e.g., a receiving apparatus and the like included in themultimedia system under a control of the controller 1513. The varioussignals and various messages received in the receiver 1515 have beendescribed with reference to FIGS. 1 to 14 and Tables 1 to 15, and adetailed description thereof will be omitted herein.

The storage unit 1517 stores various programs, various data, and thelike related to the operation related to the operation of transmittingand receiving the information related to the link layer packet carryingthe plurality of sub-streams performed in the multimedia systemaccording to an embodiment of the present disclosure under a control ofthe controller 1513. The storage unit 1517 stores various signals andvarious messages which are received by the receiver 1515 from the otherentities.

The output unit 1519 outputs various signals and various messagesrelated to the operation related to the operation of transmitting andreceiving the information related to the link layer packet carrying theplurality of sub-streams performed in the multimedia system according toan embodiment of the present disclosure under a control of thecontroller 1513. The various signals and various messages output by theoutput unit 1519 have been described with reference to FIGS. 1 to 14 andTables 1 to 15, and a detailed description thereof will be omittedherein.

While the transmitter 1511, the controller 1513, the receiver 1515, thestorage unit 1517, and the output unit 1519 are described in thetransmitting apparatus 1500 as separate units, it is to be understoodthat this is merely for convenience of description. In other words, twoor more of the transmitter 1511, the controller 1513, the receiver 1515,the storage unit 1517, and the output unit 1519 may be incorporated intoa single unit.

The transmitting apparatus 1500 may be implemented with at least oneprocessor.

An inner structure of a transmitting apparatus in a multimedia systemaccording to an embodiment of the present disclosure has been describedwith reference to FIG. 15, and an inner structure of a receivingapparatus in a multimedia system according to an embodiment of thepresent disclosure will be described with reference to FIG. 16.

FIG. 16 schematically illustrates an inner structure of a receivingapparatus in a multimedia system according to an embodiment of thepresent disclosure.

Referring to FIG. 16, a receiving apparatus 1600 may be a terminal,and/or the like.

The receiving apparatus 1600 includes a transmitter 1611, a controller1613, a receiver 1615, a storage unit 1617, and an output unit 1619. Thecontroller 1613 includes at least one processor.

The controller 1613 controls the overall operation of the receivingapparatus 1600. More particularly, the controller 1613 controls anoperation related to an operation of transmitting and receiving a signalin a multimedia system according to an embodiment of the presentdisclosure, e.g., an operation of transmitting and receiving informationrelated to a link layer packet carrying a plurality of sub-streams. Theoperation related to the operation of transmitting and receiving theinformation related to the link layer packet carrying the plurality ofsub-streams has been described with reference to FIGS. 1 to 14 andTables 1 to 15, and a detailed description thereof will be omittedherein.

The transmitter 1611 transmits various signals and various messages toother entities, e.g., a transmitting apparatus and the like included inthe multimedia system under a control of the controller 1613. Forexample, the transmitting apparatus may be a service provider and/or thelike. The various signals and various messages transmitted in thetransmitter 1611 have been described with reference to FIGS. 1 to 14 andTables 1 to 15, and a detailed description thereof will be omittedherein.

The receiver 1615 receives various signals and various messages fromother entities, e.g., a transmitting apparatus and the like included inthe multimedia system under a control of the controller 1613. Thevarious signals and various messages received in the receiver 1615 havebeen described with reference to FIGS. 1 to 14 and Tables 1 to 15, and adetailed description thereof will be omitted herein.

The storage unit 1617 stores various programs, various data, and thelike related to the operation related to the operation of transmittingand receiving the information related to the link layer packet carryingthe plurality of sub-streams performed in the multimedia systemaccording to an embodiment of the present disclosure under a control ofthe controller 1613. The storage unit 1617 stores various signals andvarious messages which are received by the receiver 1615 from the otherentities.

The output unit 1619 outputs various signals and various messagesrelated to the operation related to the operation of transmitting andreceiving the information related to the link layer packet carrying theplurality of sub-streams performed in the multimedia system according toan embodiment of the present disclosure under a control of thecontroller 1613. The various signals and various messages output by theoutput unit 1619 have been described with reference to FIGS. 1 to 14 andTables 1 to 15, and a detailed description thereof will be omittedherein.

While the transmitter 1611, the controller 1613, the receiver 1615, thestorage unit 1617, and the output unit 1619 are described in thereceiving apparatus 1600 as separate units, it is to be understood thatthis is merely for convenience of description. In other words, two ormore of the transmitter 1611, the controller 1613, the receiver 1615,the storage unit 1617, and the output unit 1619 may be incorporated intoa single unit.

The receiving apparatus 1600 may be implemented with at least oneprocessor. Further, the transmitting apparatus 1500 and the receivingapparatus 1600 may be combined to form a transceiver.

An operating method of a transmitting apparatus proposed in anembodiment of the present disclosure includes a process for generating alink layer packet including a header and a payload which correspond toan input stream, a process for generating a physical layer frameincluding the link layer packet, a process for processing the generatedphysical layer frame based on a preset scheme, and a process fortransmitting the processed physical layer frame. The payload may have aformat which is the same as the input stream, a format which isgenerated by changing the format of the input stream, or a format whichis unique according to a scheme of generating the link layer packet. Thelink layer packet generator may generate an additional link layer packetincluding information for controlling a receiver including a link layer.

A receiving apparatus proposed in an embodiment of the presentdisclosure includes a receiver for receiving a physical layer frameincluding data that an input stream is mapped to at least one signalprocessing path, and a processor for extracting a header from a linklayer packet included in the physical layer frame and processing apayload based on the extracted header and a preset scheme. The payloadmay have a format which is the same as the input stream, a format whichis generated by changing the format of the input stream, or a formatwhich is unique according to a scheme of generating the link layerpacket. A link layer packet generator of generating the link layerpacket may generate an additional link layer packet includinginformation for controlling a receiver including a link layer.

A receiving apparatus proposed in an embodiment of the presentdisclosure includes a receiver for receiving a physical layer frameincluding data that an input stream is mapped to at least one signalprocessing path, and a processor for extracting a header from a linklayer packet included in the physical layer frame and processing apayload based on the extracted header and a preset scheme. The payloadmay have a format which is the same as the input stream, a format whichis generated by changing the format of the input stream, or a formatwhich is unique according to a scheme of generating the link layerpacket. The payload may include data which is processed on a link layerand to be used for controlling a receiver including the link layer aswell as data to be delivered to an upper layer.

An operating method of a receiving apparatus proposed in an embodimentof the present disclosure includes a process for receiving a physicallayer frame including data that an input stream is mapped to at leastone signal processing path, and a process for extracting a header from alink layer packet included in the physical layer frame and processing apayload based on the extracted header and a preset scheme. The payloadmay have a format which is the same as the input stream, a format whichis generated by changing the format of the input stream, or a formatwhich is unique according to a scheme of generating the link layerpacket. The payload may include data which is processed on a link layerand to be used for controlling a receiver including the link layer aswell as data to be delivered to an upper layer.

As is apparent from the foregoing description, an embodiment of thepresent disclosure enables to transmit and receive a signal in amultimedia system.

An embodiment of the present disclosure enables to transmit and receivea signal in a multimedia system supporting a link layer protocol.

An embodiment of the present disclosure enables to transmit and receiveinformation related to a sub-stream included in a link layer packet in amultimedia system supporting a link layer protocol.

An embodiment of the present disclosure enables to transmit and receiveinformation related to a link layer packet carrying a plurality ofsub-streams in a multimedia system supporting a link layer protocol.

An embodiment of the present disclosure enables to effectively transmitand receive various types of services in a multimedia system supportinga link layer protocol.

An embodiment of the present disclosure enables to filter a sub-streamin a link layer packet thereby increasing data processing efficiency ina multimedia system supporting a link layer protocol.

Certain aspects of the present disclosure may also be embodied ascomputer readable code on a non-transitory computer readable recordingmedium. A non-transitory computer readable recording medium is any datastorage device that can store data, which can be thereafter read by acomputer system. Examples of the non-transitory computer readablerecording medium include read only memory (ROM), random access memory(RAM), compact disc ROMs (CD-ROMs), magnetic tapes, floppy disks,optical data storage devices, and carrier waves (such as datatransmission through the Internet). The non-transitory computer readablerecording medium can also be distributed over network coupled computersystems so that the computer readable code is stored and executed in adistributed fashion. In addition, functional programs, code, and codesegments for accomplishing the present disclosure can be easilyconstrued by programmers skilled in the art to which the presentdisclosure pertains.

It can be appreciated that a method and apparatus according to anembodiment of the present disclosure may be implemented by hardware,software and/or a combination thereof. The software may be stored in anon-volatile storage, for example, an erasable or re-writable ROM, amemory, for example, a RAM, a memory chip, a memory device, or a memoryintegrated circuit (IC), or an optically or magnetically recordablenon-transitory machine-readable (e.g., computer-readable), storagemedium (e.g., a CD, a DVD, a magnetic disk, a magnetic tape, and/or thelike). A method and apparatus according to an embodiment of the presentdisclosure may be implemented by a computer or a mobile terminal thatincludes a controller (including at least one processor) and a memory,and the memory may be an example of a non-transitory machine-readable(e.g., computer-readable), storage medium suitable to store a program orprograms including instructions for implementing various embodiments ofthe present disclosure.

The present disclosure may include a program including code forimplementing the apparatus and method as defined by the appended claims,and a non-transitory machine-readable (e.g., computer-readable), storagemedium storing the program. The program may be electronicallytransferred via any media, such as communication signals, which aretransmitted through wired and/or wireless connections, and the presentdisclosure may include their equivalents.

An apparatus according to an embodiment of the present disclosure mayreceive the program from a program providing device which is connectedto the apparatus via a wire or a wireless and store the program. Theprogram providing device may include a memory for storing instructionswhich instruct to perform a content protect method which has beenalready installed, information necessary for the content protect method,and the like, a communication unit for performing a wired or a wirelesscommunication with a graphic processing device, and a controller(including at least one processor) for transmitting a related program toa transmitting/receiving device based on a request of the graphicprocessing device or automatically transmitting the related program tothe transmitting/receiving device.

While the present disclosure has been shown and described with referenceto various embodiments thereof, it will be understood by those skilledin the art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the present disclosure asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A method of transmitting a packet by atransmitting apparatus in a broadcasting system, the method comprising:identifying at least one network layer packet; generating a link layerpacket based on the at least one network layer packet; and transmittingthe link layer packet, wherein the link layer packet comprises a headerand a payload, the header including a base header, wherein the baseheader includes packet type information indicating a type of the atleast one network layer packet and payload configuration informationindicating a configuration of the payload, wherein the payloadconfiguration information is set to one of: a first value indicatingthat the payload includes a single network layer packet and informationfollowing the payload configuration information is header modeinformation, and a second value indicating that the payload includes apart of a network layer packet or a plurality of network layer packetsand information following the payload configuration information issegmentation concatenation information, and wherein the header modeinformation indicates whether a first additional header is present. 2.The method of claim 1, wherein the segmentation concatenationinformation is set to one of: a first value indicating that the payloadincludes the part of the network layer packet and a second additionalheader is present, and a second value indicating that the payloadincludes the plurality of network layer packets and a third additionalheader is present.
 3. The method of claim 2, wherein the firstadditional header, the second additional header and the third additionalheader include flag information indicating whether an optional headerfor sub-stream identification is present.
 4. The method of claim 3,wherein the second additional header further includes segment sequencenumber information indicating an order of a segment carried by the linklayer packet and last segment indicator information indicating whetherthe segment is a last segment.
 5. The method of claim 4, wherein thethird additional header further includes information indicating a numberof the plurality of network layer packets included in the link layerpacket and component length information indicating a length of each ofthe plurality of network layer packets.
 6. A transmitting apparatus oftransmitting a packet in a broadcasting system, the transmittingapparatus comprising: a transceiver configured to receive and transmitdata; and at least one processor configured to: identify at least onenetwork layer packet, generate a link layer packet based on the at leastone network layer packet, and transmit the link layer packet, whereinthe link layer packet comprises a header and a payload, the headerincluding a base header, wherein the base header includes packet typeinformation indicating a type of the at least one network layer packetand payload configuration information indicating a configuration of thepayload, wherein the payload configuration information is set to one of:a first value indicating that the payload includes a single networklayer packet and information following the payload configurationinformation is header mode information, and a second value indicatingthat the payload includes a part of a network layer packet or aplurality of network layer packets and information following the payloadconfiguration information is segmentation concatenation information, andwherein the header mode information indicates whether a first additionalheader is present.
 7. The transmitting apparatus of claim 6, wherein thesegmentation concatenation information is set to one of: a first valueindicating that the payload includes the part of the network layerpacket and a second additional header is present, and a second valueindicating that the payload includes the plurality of network layerpackets and a third additional header is present.
 8. The transmittingapparatus of claim 7, wherein the first additional header, the secondadditional header and the third additional header include flaginformation indicating whether an optional header for sub-streamidentification is present.
 9. The transmitting apparatus of claim 8,wherein the second additional header further includes segment sequencenumber information indicating an order of a segment carried by the linklayer packet and last segment indicator information indicating whetherthe segment is a last segment.
 10. The transmitting apparatus of claim8, wherein the third additional header further includes informationindicating a number of the plurality of network layer packets includedin the link layer packet and component length information indicating alength of each of the plurality of network layer packets.